Functional polythiophene bearing hydroxyethyl groups and their derivatives

Poly(3-(2-hydroxyethyl)thiophene) (P3HET) was synthesized using oxidative Coupling polymerization that involved the protecting and deprotecting of hydroxyl groups but not the Chlorine Substitution or oxidative decomposition of the hydroxyl groups. The resulting P3HET exhibited good Solubility ill aprotic solvents, in contrast to the insoluble polymer product synthesized directly from the monomer, 3-(2-hydroxyethyl)thiophene (3HET). P3HET had low conductivity Clue to the strong hydrogen bonding of its hydroxyl groups. The ester-functionalized poly(3-(2-acetoxyethyl)thiophene) and poly(3-(4-pentylbenzoateethyl)thiophene) were also prepared with reasonably high molecular weights in order to examine flow this functionalization modified the physical and chemical properties of MET. These polymers exhibited better solubility in common solvents and higher conductivity than P3HET. All these polymers exhibited bathochromic shifts of their film state absorption maxima with respect to those found ill the UV-visible spectra of their solution phases. The extent of the bathochromic shift was found to vary with the lengths of the side chains of the ester-functionalized polymers.